Method of securing courses on double cylinder knitting machines

ABSTRACT

In the knitting feed immediately following the feed in which the yarn was caught on the empty needles of both the upper and lower needle cylinders, the caught yarn is held on the empty needles by the operating needle shafts, during their transition from the closing to the laying positions and below the needle latches, by means of knocking-over bits which are in their rear position. Concomitantly this yarn is caught on the needle hooks in the opposite cylinder, the needles of such other cylinder being in their inoperative position, and the yarns of this knitting feed being laid into the needle hooks which are in their operative position.

United States Patent 1 Zahradka et al.

[ METHOD OF SECURING COURSES ON DOUBLE CYLINDER KNITTING MACHINES [75] Inventors: Pavel Zahradka, Trebic; Milan Petranek, Starec; Jiri Hrabanek, Nova Ves, all of Czechoslovakia [73] Assignee: Elitex, Zavody textilniho strojirenstvi, generalni reditelstvi, Liberec, Czechoslovakia [22] Filed: June 9, 1972 [21] Appl. No.: 261,548

[30] Foreign Application Priority Data June 14, 1971 Czechoslovakia 4348-71 [52] U.S. Cl. 66/14 [51] Int. Cl D04b 9/10 [58] Field 01" Search 66/14, 172

[56] References Cited UNITED STATES PATENTS 2,150,336 3/1939 Miller et a1. 66/14 June 17, 1975 Primary Examiner-Ronald Feldbaum Attorney, Agent, or FirmMurray Schaffer [5 7] ABSTRACT In the knitting feed immediately following the feed in which the yarn was caught on the empty needles of both the upper and lower needle cylinders, the caught yarn is held on the empty needles by the operating needle shafts, during their transition from the closing to the laying positions and below the needle latches, by means of knocking-over bits which are in their rear position. Concomitantly this yarn is caught on the needle hooks in the opposite cylinder, the needles of such other cylinder being in their inoperative position, and the yarns of this knitting feed being laid into the needle hooks which are in their operative position.

4 Claims, 17 Drawing Figures PATENTEIJJUN 1 7 I975 SHEET PATENTEDJLIMY 1975 3889.492

SHEET 4 FIG.6

METHOD OF SECURING COURSES ON DOUBLE CYLINDER KNITTING MACHINES BACKGROUND OF INVENTION The present invention relates to a method of finishing knitwork on a double cylinder circular knitting machine.

in particular, the present invention relates to a method of securing yarn which is caught on the empty needles of a two cylinder circular knitting machine before and during the laying of the welt yarn into needle hooks, so as to form a course following the last course formed of the knitwork yarn caught on the empty needles in which the yarns are secured.

In the operation of two cylinder knitting machines as known heretofore, the yarn is always caught on empty needles by a single knitting feed. After dividing the empty needles, i.e. the needles without yarn, in a 1:1 arrangement in each cylinder, a start-up course having a 1:1 structure is performed in the following feed. In this following revolution, needles in the upper needle cylinder are placed out of operation and so-called tubular course is formed by knitting with the needles from only the lower needle cylinder, the tubular course securing the preceding course. Rubber yarn may be added to the yarn of the following course, if desired.

This method, when employed in multifeed knitting machines, has the disadvantage in that the needles used to form the start-up course pass through further feeds of the machine in which the knocking-over bits are automatically moved into opened or forward position or moved to a rearward position relative to the needle cylinder needle and thereafter closed. In the process, the caught yarn is released and becomes separated from the knocking-over bits. Due to the fact that the feed which forms the heel and toe portions of the product is used as the set-on or make-up feed, the needles pass from the closing position (i.e. wherein the yarn is to be layed thereon) into the laying position and further into the sinking position in the station in which the knocking-over bits are opened so that the yarn is not retained on the needle shaft. The latches of the needles penetrate the released yarn instead of forming loops upon knitting of the tubular course, particularly in the case of the knitting of a welt without rubber which customarily helps the withdraw] of set-on yarn. Pressurized air and similar means have previously been utilized to eliminate this disadvantage.

The purpose of the present invention is to overcome the said disadvantage by normal knitting means without using pressurized air or the introduction of rubber yarn.

Further objects and advantages will be described in the following description.

SUMMARY OF THE lNVENTION According to the present invention, in the knitting feed immediately following the feed in which the yarn was caught on the empty needles of both the upper and lower needle cylinders, the caught yarn is held on the empty needles by the operating needle shafts, during their transition from the closing to the laying positions and below the needle latches, by means of knockingover bits which are in their rear position. Concomitantly this yarn is caught on the needle hooks in the opposite cylinder, the needles of such other cylinder being in their inoperative position, and the yarns of this knitting feed being laid into the needle hooks which are in their operative position.

Full details of the method of and device for performing the method according to the one embodiment of the present invention are described, by way of example, in the following specification and shown in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 illustrates a cam system for controlling the butts of needle jacks, associated with the upper and lower needle cylinders with an indication of the paths of the upper controlling jack butts and the catching of yarns in the separate knitting feeds, as well as an indication of the period for the withdrawal of the knockingover bits; 1

FIG. 2 shows the structure of the first two courses of the knitwork;

FIG. 3 shows the structure of the first two courses of the knitwork incorporating knitted-in rubber yarn with the yarn of that feed which performs the set-on; and

FIG. 4 shows the structure of the first two courses of the knitwork together with knitting-in rubber yarn with the yarn of that feed in which securing of the yarn of the first course is performed.

FIG. 5 is an enlarged view of a section of needles and knock-over bits, taken at point E of FIG. 1;

FIG. 6 is a view similar to FIG. 5 taken at point B;

FIG. 7 is a schematic representation of the needles and loop formation of the first feed, yarn P FIG. 8 is a view similar to FIG. 7 showing the second feed, yarn P and FIG. 9 shows the looping of the first securing course.

FIGS. 10a through are illustrations of the needle cylinder in cross section, at the respective knitting positions A, B, C and D shown in FIG. 1, and

FIGS. 108 through 123 are partial views of the cam of FIG. 1 at those positions.

DESCRIPTION OF INVENTION As is well known, two cylinder circular knitting machines generally comprise a pair of superimposed and axially aligned needle cylinders. Each such cylinder is provided with a plurality of circumferentially spaced and vertically extending slots. Within each of such slots there is mounted a knitting needle and an associated needle jack 40. The said needle jacks are reciprocable within said needles so as to control the vertical movement of the needles. The needle jacks are provided with upper and/or lower butt portions. Surrounding each cylinder is a cam system designed to receive the said jack butts and thereby control the vertical travel of said jacks, and the knitting pattern of the needles. Such a cam system is shown schematically in FIG. 1. In the Figure the direction of rotation of the needle cylinder is illustrated by arrow S. The first knitting feed in the lower needle cylinder generally aligned at A, consists of a central laying cam 1, left sinker cam 2 and right sinker cam 3, a left stitch cam 4 and a right stitch cam 5, a left auxiliary cam 6 and a right auxiliary cam 7 and a lower cam 8. The first knitting feed in the upper needle cylinder consists of a sinker cam 9, a stitch cam 10 and an auxiliary cam 11. Associated with the first knitting feed in the cam system of the lower needle cylinders are prearranged cams 12, 13 and 14 while cams 15, 16 and 17 are arranged in the system of the upper needle cylinder.

The second knitting feed (generally position B) in the lower needle cylinder consists of a sinker cam 18, a stitch cam 19 and an auxiliary cam 20. With that feed are prearranged a heel cam 21, a cam 22 for imparting a closing position, an auxiliary cam 23 and cams 24, 25, and 26. The second knitting feed in the upper needle cylinder consists of a sinker cam 27, a stitch cam 28 and an auxiliary cam 29. To this feed there is provided a cam 30 for controlling the closing position, and cams 31, 32 and 33 and a transfer cam 34 cooperating with lower butts of the needle jacks by which the upper needles are introduced into the second system. Once so introduced the upper butts of the upper needles cooperate with cam 30.

In the first knitting feed, yarn P is laid, by means such as a yarn carrier into the needle hooks at point B. In the second knitting feed, yarn P is laid into the needle hooks at point B.

As seen in FIG. 1 the knock-over sinker or butts 36, are controlled by the movement of their butts 36' in the path defined by the cam rings 37 and 38.

The knocking-over bits are closed, i.e.: withdrawn or are drawn into their rear position, respectively, at point C, and are opened, i.e.: advanced to or take up their front position, respectively, at point D.

The path of the upper control butts of the needle jacks 40 in the upper needle cylinder, or the passage of the control butts through the cam system, respectively, is denoted by the line and the a and the path of the upper control butts in the lower needle cylinder is denoted by the line b.

In conventional manner the fabric is knitted in the machine until the final knit course is obtained and the yarn is caught on alternate needles, the free needles, i.e. needles without yarn) are further distributed in a 1:1 relationship into both the lower and upper needle cylinder by means of conventional transfer elements. The securing course may then be initiated, and beginning with a pre-selected needle, the yarn P is caught at point A and carried out on all needles which are then cleared to their lowest position (FIG. 7). As the needle cylinders rotate yarn P is drawn in by means of cams 2 and 4 as well as cams 9 and acting on the jack 40. At point C, the knocking-over bits are withdrawn and yarn P is held on the needles, as seen in FIG. 2.

The needles of the lower needle cylinder reach the closing position by means of cam 22. At such time yarn P is under the latches of the needles. Simultaneously, the needles of the upper needle cylinder are released in their stitch position by means of transfer cm 34, which is inoperative, yarn P remaining closed inside the needle hooks, the upper control butts of the jacks running along path a between cams and 31.

At point B, yarn P is brought into the hooks of the needles in the lower needle cylinder, while the upper needles remain in sinking position. The lower needles are then cleared and form stitches of yarn P (FIG. 8). The knocking-over bits remain in the rear position, and thus upon movement of the needles by means of the heel cam 21 yarn P1 is retained on the needle shafts. At points B, B" and B as seen in FIG. 6 the knock-over bits 36 take their extreme rear position and the needles B and 35B in the lower cylinder (FIG. 6) are drawn upwardly by means of the jacks moving in path b. As the knock over bits 36 are closed, the yarn P rests against the needle shanks 35B and 35b and is caught in the beard 35" of the alternative needle in the upper cylinder which, cammed in path a is moving horizontally. The yarn thus has no chance of being pinned within the needle latches.

As seen in FIG. 5 the knock-over bits 36 are moved forwardly by the cam rings so that the points E, E" and E the yarns P would be laid into the needles 35 of the second system. If the needles were empty at this time the yarn P would be pinned to the needle latches as drawn upwardly due to the open knock-over bits. But because the first course has already been knotted, this does not happen and as seen in FIG. 5, the yarn P is pressed against the shanks of needle 35E and 35 and the beard shank of needle 35" by the action of the loops formed by existing yarn P. (not shown in drawing). Only at point D are the knockingover bits opened. Thus, the retaining of yarn P, on the needle shafts is guaranteed.

In the second knitting feed, yarn P which is caught by the needles of the lower needle cylinder by means of cams 18, 19 and 20, is interlocked with yarn P In the following can be added to yarn P or P (FIGS. 3 and 4) as desired.

Another view of the present method of operation is seen in FIGS. 10-12.

It is to be noted that the securing of yarn P, on the needle shafts upon the laising of yarn P cannot be secured also in an opposite relationship of the needles of both the upper and lower needle cylinders, because the .lower needles become inoperative and the tubular course from yarn P is formed by the needles of the upper needle cylinder.

It will thus be seen that a simple method is provided for the securing of yarn which is caught on the empty needles. The method comprises holding the caught yarn on the shafts of the needles during rotation of the cylinders and while the needles are in operative position, continuing the holding of the first yarn on the needle shaft during the transition from their closing to laying positions below the latches of said needles by means of knocking-over bits held in their rear position, simultaneously catching the caught yarn on the hooks of the needles of the second cylinder which are at such time in their inoperative position, and laying a second yarn into the hooks of such needles as are in their operative position.

The present description is illustrative of the method, as applied to a double needle cylinder knitting machine which is conventional in all other aspects of structure and function. Accordingly, the description has not detailed the structure. The scope of the invention should not be limited by the description but solely by the appended claims.

What is claimed:

1. A method of knitting on a two cylinder circular knitting machine so as to secure a first yarn which has been caught on the empty needles of a first of said cylinders before and during the laying of a second yarn into the hooks of said needles for the formation of a succeeding course, comprising holding said first yarn on the shafts of said needles during rotation of said cylinders and while said needles are in operative position, continuing the holding of said first yarn on said needle shafts during the transition from their closing to laying positions below the latches of said needles by means of knocking-over bits held in their rear position, simulta neously catching said first yarn on the hooks of the needles of the second cylinder which are at such time in their inoperative position, said second yarn then being laid into the hooks of such needles as are in their operative position.

2. A method according to claim 1, wherein said first yarn is caught upon a selected needle, said cylinders are rotated so as to draw the yarn axially along one of said cylinders, closing said knocking-over bits to hold said yarn on the needles, continuing rotation of said cylinders such that the needles of the lower of said cylinders are cammed to their closing position and said yarn is under the latches of said needles, the needles of the upper of said cylinders being simultaneously released in their stitch position through the action of a transfer cam maintaining the knocking-over bits in their rear position, camming said needles of said lower cylinder into the laying position while retaining said first yarn on the shaft of said needles, introducing a second yarn into the hooks of the needles of said lower cylinder, and thereafter opening said knocking-over bits.

3. A method according to claim 2, wherein said first and second yarns are interlocked.

4. A method according to claim 1, wherein a third rubber yarn is fed to said machine together with said first or second yarn. 

1. A method of knitting on a two cylinder circular knitting machine so as to secure a first yarn which has been caught on the empty needles of a first of said cylinders before and during the laying of a second yarn into the hooks of said needles for the formation of a succeeding course, comprising holding said first yarn on the shafts of said needles during rotation of said cylinders and while said needles are in operative position, continuing the holding of said first yarn on said needle shafts during the transition from their closing to laying positions below the latches of said needles by means of knocking-over bits held in their rear position, simultaneously catching said first yarn on the hooks of the needles of the second cylinder which are at such time in their inoperative position, said second yarn then being laid into the hooks of such needles as are in their operative position.
 2. A method according to claim 1, wherein said first yarn is caught upon a selected needle, said cylinders are rotated so as to draw the yarn axially along one of said cylinders, closing said knocking-over bits to hold said yarn on the needles, continuing rotation of said cylinders such that the needles of the lower of said cylinders are cammed to their closing position and said yarn is under the latches of said needles, the needles of the upper of said cylinders being simultaneously released in their stitch position through the action of a transfer cam maintaining the knocking-over bits in their rear position, camming said needles of said lower cylinder into the laying position while retaining said first yarn on the shaft of said needles, introducing a second yarn into the hookds of the needleS of said lower cylinder, and thereafter opening said knocking-over bits.
 3. A method according to claim 2, wherein said first and second yarns are interlocked.
 4. A method according to claim 1, wherein a third rubber yarn is fed to said machine together with said first or second yarn. 